From Political Wire:
Matthew Yglesias: "The Republicans do this the right way. The Senate Republican caucus is organized, like the House caucuses of both parties, like a partisan political organization whose objective is to advance the shared policy objectives of the party. The Senate Democratic caucus, by contrast, is organized like a fun country club trying to recruit members. Join Team Democrat and Vote However You Want Without Consequence! But it’s no way to get things done."
Steve Benen: "It often goes overlooked, but it’s worth remembering that the Senate Republican caucus, unlike Senate Democrats, have mechanisms in place to enforce party unity and discipline. When Democrats break party ranks on key bills, there are no consequences. Those who let GOP leaders down, however, know in advance that enticements like committee positions are very much on the line."